int butt1 = 12;  
int butt2 = 13;
int led1 = 4;
int led2 = 7;
int led3 = 8;
int prev = 1;

int A, B, iff = 0;

void setup(){
  pinMode(led1, OUTPUT);
  pinMode(led2, OUTPUT);
  pinMode(led3, OUTPUT);
  pinMode(butt1, INPUT);
  pinMode(butt1, INPUT);
  digitalWrite(led1, 0);
  digitalWrite(led2, 0);
  digitalWrite(led3, 0);
  digitalWrite(butt1, 1);
  digitalWrite(butt2, 1);
  Serial.begin(9600);
}

void loop(){
  A = digitalRead(butt1);
  B = digitalRead(butt2);
  Serial.print(A); Serial.print(" "); Serial.print(B); Serial.print(", Prev:"); Serial.println(prev);
  
  if (B == 0 && prev == 1){
      iff = !iff;
  }
  prev = B;
  
  if (A == 0 && B == 0){
    digitalWrite(led1, 0);
    digitalWrite(led2, 0);
    digitalWrite(led3, 1);
  } else {

    while (A == 0 && B == 1){
      digitalWrite(led1, 1);
      delay(250);
      digitalWrite(led1, 0);
      delay(250);
      A = digitalRead(butt1);
    }
    
    if (A == 1 && B == 0){
      digitalWrite(led1, 0);
      digitalWrite(led2, iff);
    }
    digitalWrite(led3, 0);
  }
}